Amazon.co.uk offers The Tudors Complete Series on Blu-ray for $19.53 (£16.02). During checkout, it drops to $16.27 (£13.35). With $3.75 (£3.08) for shipping, that's $8 under our mention from last December and $30 less than the best price we could find. It features all four seasons on 12 discs.
Of note, although the episodes themselves will play on US Blu-ray players, the extras and special features may not.